Referring to FIGS. 1-4, a typical Venetian blind 10 of the prior art is shown to comprise a head rail 11, a tilting device 13, three tilt cords 14, a bottom rail, a plurality of slats 16, two draw cords 17, and a cord pulley retainer 18.
The head rail 11 is fastened securely to a wall or a window frame. The tilting device 13 is mounted pivotally in the head rail 11. Each of the three tilt cords 14 has one end fastened to the tilting device 13 and another end that is suspended. Each tilt cord 14 is composed of two slings 141 parallel to each other. Located between the two slings 141 are a plurality of connection lines 142 which are equidistantly spaced. The bottom rail 15 is disposed at the bottom ends of the tilt cords 14 and is parallel to the head rail 11. The slats 16 are disposed respectively between the two slings 141 of the tilt cord 14 and are supported by the connection lines 142 such that the slats 16 are suspended equidistantly. Each of the slats 16 is provided with two through holes 161 corresponding in location to the tilt cords 14. The through holes 161 of the adjacent slats 16 are corresponding in location to one another. The tilting device 13 is used to cause the slings 141 to move upwards or downwards so as to regulate the position of the slats 16 in order to keep out the light. Each of the two draw cords 17 has one end that is fastened to the bottom rail 15 and another end that passes through the through holes 161 of the slats 16 before emerging via the head rail 11. The draw cords 17 are used to raise or lower the bottom rail 15 so as to draw up or lower the slats 16. The cord pulley retainer 18 is disposed in one side of the head rail 11 for retaining and locating the draw cords 17.
The through holes 161 of the slats 16 are oval in shape and situated on a center line 162 of the slats 16, as shown in FIG. 4. As a result, the slats 16 are not interfered by the draw cords 17 at the time when the slats 16 are set together at an angle to regulate the light. However, when the slats 16 are adjusted to be in an upright position to keep out the light, as shown in FIG. 3, the through holes 161 of the Venetian blind 19 are so exposed that they allow the light to pass therethrough and that they can be improperly used as peep holes.